Strange ARC/Swap/CPU on yesterday's -CURRENT
Roman Bogorodskiy
novel at FreeBSD.org
Wed Mar 7 10:39:25 UTC 2018
Danilo G. Baio wrote:
> On Tue, Mar 06, 2018 at 01:36:45PM -0600, Larry Rosenman wrote:
> > On Tue, Mar 06, 2018 at 10:16:36AM -0800, Rodney W. Grimes wrote:
> > > > On Tue, Mar 06, 2018 at 08:40:10AM -0800, Rodney W. Grimes wrote:
> > > > > > On Mon, 5 Mar 2018 14:39-0600, Larry Rosenman wrote:
> > > > > >
> > > > > > > Upgraded to:
> > > > > > >
> > > > > > > FreeBSD borg.lerctr.org 12.0-CURRENT FreeBSD 12.0-CURRENT #11 r330385: Sun Mar 4 12:48:52 CST 2018 root at borg.lerctr.org:/usr/obj/usr/src/amd64.amd64/sys/VT-LER amd64
> > > > > > > +1200060 1200060
> > > > > > >
> > > > > > > Yesterday, and I'm seeing really strange slowness, ARC use, and SWAP use and swapping.
> > > > > > >
> > > > > > > See http://www.lerctr.org/~ler/FreeBSD/Swapuse.png
> > > > > >
> > > > > > I see these symptoms on stable/11. One of my servers has 32 GiB of
> > > > > > RAM. After a reboot all is well. ARC starts to fill up, and I still
> > > > > > have more than half of the memory available for user processes.
> > > > > >
> > > > > > After running the periodic jobs at night, the amount of wired memory
> > > > > > goes sky high. /etc/periodic/weekly/310.locate is a particular nasty
> > > > > > one.
> > > > >
> > > > > I would like to find out if this is the same person I have
> > > > > reporting this problem from another source, or if this is
> > > > > a confirmation of a bug I was helping someone else with.
> > > > >
> > > > > Have you been in contact with Michael Dexter about this
> > > > > issue, or any other forum/mailing list/etc?
> > > > Just IRC/Slack, with no response.
> > > > >
> > > > > If not then we have at least 2 reports of this unbound
> > > > > wired memory growth, if so hopefully someone here can
> > > > > take you further in the debug than we have been able
> > > > > to get.
> > > > What can I provide? The system is still in this state as the full backup is slow.
> > >
> > > One place to look is to see if this is the recently fixed:
> > > https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=222288
> > > g_bio leak.
> > >
> > > vmstat -z | egrep 'ITEM|g_bio|UMA'
> > >
> > > would be a good first look
> > >
> > borg.lerctr.org /home/ler $ vmstat -z | egrep 'ITEM|g_bio|UMA'
> > ITEM SIZE LIMIT USED FREE REQ FAIL SLEEP
> > UMA Kegs: 280, 0, 346, 5, 560, 0, 0
> > UMA Zones: 1928, 0, 363, 1, 577, 0, 0
> > UMA Slabs: 112, 0,25384098, 977762,102033225, 0, 0
> > UMA Hash: 256, 0, 59, 16, 105, 0, 0
> > g_bio: 384, 0, 33, 1627,542482056, 0, 0
> > borg.lerctr.org /home/ler $
> > > > > > Limiting the ARC to, say, 16 GiB, has no effect of the high amount of
> > > > > > wired memory. After a few more days, the kernel consumes virtually all
> > > > > > memory, forcing processes in and out of the swap device.
> > > > >
> > > > > Our experience as well.
> > > > >
> > > > > ...
> > > > >
> > > > > Thanks,
> > > > > Rod Grimes rgrimes at freebsd.org
> > > > Larry Rosenman http://www.lerctr.org/~ler
> > >
> > > --
> > > Rod Grimes rgrimes at freebsd.org
> >
> > --
> > Larry Rosenman http://www.lerctr.org/~ler
> > Phone: +1 214-642-9640 E-Mail: ler at lerctr.org
> > US Mail: 5708 Sabbia Drive, Round Rock, TX 78665-2106
>
>
> Hi.
>
> I noticed this behavior as well and changed vfs.zfs.arc_max for a smaller size.
>
> For me it started when I upgraded to 1200058, in this box I'm only using
> poudriere for building tests.
I've noticed that as well.
I have 16G of RAM and two disks, the first one is UFS with the system
installation and the second one is ZFS which I use to store media and
data files and for poudreire.
I don't recall the exact date, but it started fairly recently. System would
swap like crazy to a point when I cannot even ssh to it, and can hardly
login through tty: it might take 10-15 minutes to see a command typed in
the shell.
I've updated loader.conf to have the following:
vfs.zfs.arc_max="4G"
vfs.zfs.prefetch_disable="1"
It fixed the problem, but introduced a new one. When I'm building stuff
with poudriere with ccache enabled, it takes hours to build even small
projects like curl or gnutls.
For example, current build:
[10i386-default] [2018-03-07_07h44m45s] [parallel_build:] Queued: 3 Built: 1 Failed: 0 Skipped: 0 Ignored: 0 Tobuild: 2 Time: 06:48:35
[02]: security/gnutls | gnutls-3.5.18 build (06:47:51)
Almost 7 hours already and still going!
gstat output looks like this:
dT: 1.002s w: 1.000s
L(q) ops/s r/s kBps ms/r w/s kBps ms/w %busy Name
0 0 0 0 0.0 0 0 0.0 0.0 da0
0 1 0 0 0.0 1 128 0.7 0.1 ada0
1 106 106 439 64.6 0 0 0.0 98.8 ada1
0 1 0 0 0.0 1 128 0.7 0.1 ada0s1
0 0 0 0 0.0 0 0 0.0 0.0 ada0s1a
0 0 0 0 0.0 0 0 0.0 0.0 ada0s1b
0 1 0 0 0.0 1 128 0.7 0.1 ada0s1d
ada0 here is UFS driver, and ada1 is ZFS.
> Regards.
> --
> Danilo G. Baio (dbaio)
Roman Bogorodskiy
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 455 bytes
Desc: not available
URL: <http://lists.freebsd.org/pipermail/freebsd-current/attachments/20180307/e65f61bb/attachment.sig>
More information about the freebsd-current
mailing list